Urinary bladder

The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x

The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x

The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x

The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x

The fibrous adventitia contains adipose tissue, blood vessels and nerves. The superior and lateral portions of the bladder are covered by reflections of the peritoneum, forming a serosa, as present here.